The present invention relates to a novel and useful dental impression dam system.
Dental impression trays are employed generally to hold fluid impression material. The tray and material are inserted into a patient""s mouth, and pressed onto the teeth of the patient to produce a pattern representing a dental formation. The fluid dental impression material then hardens and is used to produce a crown, bridge, and the like.
In most cases, the dental practitioner must introduce an adequate amount of material to produce a proper dental impression. However, in certain cases, excess material may be employed to insure against a deficiency of dental impression material during this process. However, the use of excess material creates a problem of the dental impression material overflowing the tray and gagging or choking the patient.
This problem has been recognized and various impression trays have been devised to correct the same. For example, U.S. Pat. Nos. 273,833, 4,652,237, and European Patent Application EPO 95038282 describe dental impression trays having dams at the end portions to prevent movement of impression material into the throats of the user.
U.S. Pat. Nos. 210,407 and 538,204 show dental impression trays which employ a soft dam material at the end portions thereof to hold the impression material in the tray and cushion the bite of the user on the impression material.
U.S. Pat. No. 3,534,475 shows an attachment for a dental impression tray in the form of a series of hooks which are meant to imbed excess dental impression tray material and hold the same away from the throat of the user.
A problem still remains in dental impression cup and trays in that the dams do not prevent the formation of a layer of excess dental impression material outside the tray which may separate from the prior art demand the main body of the impression material and cause a choking or gagging problem with the user or patient.
A dental impression dam system which solves the problems noted in the prior art would be a notable advance in the dental field.
In accordance with the present invention a novel and useful dental impression tray system is herein provided.
The system of the present invention utilizes an open tray which forms a basin for dental impression material. Of course, the dental impression material, when introduced, would be fluid, hardening with time. The tray includes a bottom and a wall portion extending outwardly from the bottom leaving a gap in the wall portion at one of the extremities of the tray, usually the ID closest to the patient""s throat when the dental impression tray is employed to make a dental bridge, crown, or the like.
A flexible band of material is employed to bridge the gap in the wall portion of the tray. The flexible band of material is selected to interact with the dental impression material to form a unit. Thus, the band of material must be porous to the dental impression material and be able to hold the same during and after hardening.
Means is also employed for adhering the flexible band of material to the open tray wall portions. Such adhering means may take the form of an adhesive which coats the porous flexible band of material without closing the pores of the same. Thus, the adhesive does not interfere with the penetration of the dental impression material with the band and the formation of a unit when the dental impression material hardens.
The dental impression tray of the present application may also be formed with openings to relieve the hydraulic pressure imposed by the dental impression material and to permit excess material to flow outwardly away from the end of the tray basin. In addition, soft tissue forming a portion of the dental impression is not distorted when hydraulic pressure is relieved through these openings.
It may be apparent that a novel and useful dental impression tray dam system has been hereinabove described.
It is therefore an object of the present invention to provide a dental impression tray dam system which utilizes flexible band to enclose the dental tray basin at its end portion and yet allow the patient to provide a dental impression without interference.
Another object of the present invention is to provide a dental impression tray dam system which utilizes a flexible band of porous material to enclose the basin of the dental tray in which interacts with the dental tray impression material to form a unit or unitary member, obviating excess dental impression tray material from entering the throat of the patient.
A further object of the present invention is to provide a dental impression tray dam system which is capable of capturing the impressions of edentulous and dentulous areas of the same arch of the patient.
A further object of the present invention is to provide a dental impression tray dam system which is usable with a variety of dental impression materials.
Another object of the present invention is to provide a dental impression tray which employs a dam system to direct the hydraulic pressure of the dental impression material toward the tissue and teeth resulting in improved detail of the dental impression.
Yet another object of the present invention is to provide a dental impression tray dam system which utilizes a band of soft porous material that can be hygienically or aseptically dispensed.
A further object of the present invention is to provide a dental impression tray dam system in which the movement of dental impression material down the throat of the patient is eliminated, while providing the practitioner with an excellent dental impression in both edentulous and dentulous areas of the same arch.
Another object of the present invention is to provide a dental impression tray which obtains a detailed dental impression, especially in the 2nd and 3rd molar areas.
Yet another object of the present invention is to provide a dental impression tray that eliminates an air bubble void at the 2nd and 3rd molar areas.
The invention possesses other objects and advantages especially as concerns particular characteristics and features thereof which will become apparent as the specification continues.